Nano-capsule

It was found that the nanocapsules are formed in a miniemulsion process by a variety of monomers in the presence of larger amounts of a hydrophobic oil. Hydrophobic oil and monomer form a common miniemulsion before polymerization, whereas the polymer is immiscible with the oil and phase-separates throughout polymerization to form particles with a morphology consisting of a hollow polymer structure surrounding the oil. The differences in the hydro-philicity of the oil and the polymer turned out to be the driving force for the formation of nano capsules. 

Inner core structure responds to communication between nano-capsule walls, G. W. V. Cave, J. Antesberger, L. J. Barbour, R. M. McKinlay and J. L. Atwood, Angew. Chem. Int. Ed. Engl., 2004, 43, 5263. 

Type of reaction supramolecular complexation Reaction condition solid-state Keywords pyrogallo[4]arene, nano-capsule... 

Figure 18.11 General procedure of different methods for the preparation of nano-capsules [52], Drug reservoir...

Capsules smaller than 1 ixm are called nano-capsules because their size is measured in nanometers. When the core and the coating are not really separated, the microcapsule, or nanocapsule, is called microparticle, or nanoparticle. 

In another study, radiolabeled and fluorescent lipid nanocapsules were synthesized by using a phase inversion process that followed the formation of an o/w microemulsion containing triglycerides, lecithins, and a nonionic surfactant. Results of the experiment revealed that lipid nanocapsules were rapidly accumulated within cells through active and saturating mechanisms. Nanocapsules could bypass the endo-lysosomal compartment with only 10% of the cell-internalized fraction found in isolated lysosomes. When nanocapsules were loaded with paclitaxel, smallest lipid nano capsules (LNCs) also were found to trigger the best cell death activity. ... 

Landfester, K., A. Musyanovych, and V. Mailander, From polymeric particles to multifunctional nano-capsules for biomedical applications using the miniemulsion process. J. Polym. Sci. A Polym. Chem. 48 (2010) 493-515. 

RR. Catarina, J.N. Ronald, J.R. Antonio, Nano capsulation 1. Method of preparation of drug -loaded polymeric nanoparticles nano technology. Biology and Medicine 2 (2006) 8-21. 

An intriguing eflect with CB7 has been observed in the case of thioflavin T (ThT), a flbril diagnostic dye, in the presence of metal cations. ThT forms both 1 1 (CB7 ThT) and 2 1 [(CB7)2 ThT] fluorescent complexes. Addition of competitive guests like metal cations to the 1 1 complex caused the expected fluorescence intensity decrease. However, addition of metal ions to the 2 1 complex leads to an unusual enhancement of the emission (> 270-fold in the presence of Ca + and > 160-fold in the presence of Na ). An in-depth investigation showed that in the latter case a cooperative metal ion binding to the 2 1 complex rather than competition takes place and leads to a highly fluorescent supramolecular nano capsule (see Scheme 27). ... 

Gibb CLD, Gibb BC. Templated assembly of water-soluble nano-capsules Inter-phase sequestration, storage, and separation of hydrocarbon gases. J Am Chem Soc 2006 128 16498-9. 

R. Mossotti, A. Ferri, R. Innocenti, T. Zelenkova, F. Dotti, D. Marchisio, and A. A. Barresi, Cotton fabric functionalization with menthol/PCL micro- and nano-capsules for comfort improvement. Journal of Microencapsulation, submitted (2015). 

Checot, E, Lecommandoux, S., Klok, H. A. and Gnanou, Y. (2003) From supramolec-ular polymersomes to stimuli-responsive nano-capsules based on poly(diene-b-peptide) diblock copolymers. Eur Phys J E Soft Matter, 10,25-35. 

Of the velcrands shown in Fig. 9.18, De Mendoza s benzimidazolone tetra-car-bamide) velcrand 47 (R = n-CnH23, X = O) is perhaps the least explored. In large part this can be attributed to its poor solubility. This point not withstanding, 47 has been shown to dimerize in organic solvents and entrap guests within the corresponding nano-capsule [154b, 192]. 

Fig. 31.10 (a) Diagram of PBA encapsulated in a hexameric PgCe nano-capsule [44c]. (b) View of the ADMA channels (space-filling representation C gray, N blue) formed by fluorophore intercalation between walls of neighbouring nano-capsules (stick representation C gray, O red). The PgCg hexyl chains proximate to the ADMA channels are shown in yellow, whilst all others were removed for clarity [44d]... 

An intriguing class of hexameric capsules are the hybrid systems based on metal organic pyrogallol[4]arene nano-capsules (MONCs) [57, 58], These systems were recently the subject of several reviews [57] but in recent years the field have witness a tremendous advancement, mostly by the group of Atwood. The first example of a MONC system was obtained by reacting C-proyl-3-ol-pyrogallol[4]arene obtained using the reaction shown in Fig. 31.13a with copper(II) nitrate [58a]. From the... 

New types of molecular van der Waals nano-capsules were obtained by functionalization of upper rim of the calix[4]arene moiety with long alkyl chain ester... 

Antesberger J, Cave GWV, FerrareUi MC, Heaven MW, Raston CL, Atwood JL (2005) Solvent-free, direct synthesis of supramolecular nano-capsules. Chem Commun 892-894... 

Dalgamo SJ, Szabo T, Siavosh-Haghighi A, Deakyne CA, Adams JE, Atwood JL (2009) Exploring the limits of encapsulation within hexameric pyrogallol[4]arene nano-capsules. Chem Commun 1339... 

FIGURE 47. Polyhedral representation of nano-capsules that are formed by 12 pentagons (P) and 30 linkers.(L). P = [(Mo)Mo502i(H20)6] and in the present case L = [Mo204(CH3COO)]. (Reprinted with permission from ref. 101.)... 

Nanocapsules, also known as hollow nanoparticles or nanospheres, are submicrometric colloidal objects composed of a liquid core (an internal phase) surrounded by a thin silicone shell (a membrane) (see Figure 4.2B). Hollow nanoparticles are potentially useful for encapsulation of various chemical molecules, Hving cells, or enzymes [26]. The following properties of nano capsules made their application very attractive ... 

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